Precast, prestressed concrete pilings (PPCP) are commonly used for deep foundations required under bridges, buildings, and marine structures. Every year millions of feet of precast pile are produced in the United States and driven as the anchor of deep foundations on land and in water. Some reasons for using piles as a foundation type include the application of substantial loading on the earth, inadequate structural properties or capacities of the soil, and constraints initiated by the placement of the structure on the site. Advantages for using precast piles include their exceptional structural properties from the use of high strength materials, an unrestrictive pile section size or capacity, along with uniformity and quality due to production in controlled conditions, and resistance to corrosion and durability to the environment.
Generally, PPCPs are designed, manufactured, and supplied to a project in single, long units. This approach limits their applicability to otherwise well-suited projects. Problems that arise from using very long precast piles include, for example, an immense weight and length of the piles, leading to substantial cost and difficulty associated with transportation and its handling, and increased cracking, which requires repairing or replacement of the piles. Another complication with the use of precast piles is the need for each pile length to be accurately calculated in order to minimize waste while achieving the required structural capacity. Problems can result from unexpected geotechnical conditions, found by field investigation, requiring a decrease or increase in a pile's length at the site. Currently, the methods for shortening or extending a precast pre-stressed concrete pile are complex and expensive, in contrast to alternate material counterparts (e.g. timber, steel, reinforced concrete).